Saint Bernard: "invite to the feast whomever you find."

‘My friend, how is it that you came in here without a wedding garment?’

-- Mt 22:1-14

First Holy Communion. Having become a child of God clothed with the wedding garment, the neophyte is admitted "to the marriage supper of the Lamb" and receives the food of the new life, the body and blood of Christ. The Eastern Churches maintain a lively awareness of the unity of Christian initiation by giving Holy Communion to all the newly baptized and confirmed, even little children, recalling the Lord's words: "Let the children come to me, do not hinder them." The Latin Church, which reserves admission to Holy Communion to those who have attained the age of reason, expresses the orientation of Baptism to the Eucharist by having the newly baptized child brought to the altar for the praying of the Our Father.

-- CCC 1244